Neck pain is sometimes caused by the pressure of a ligament bearing against the spinal cord. The pressure can be surgically relieved by debulking, i.e., removing some of the nucleus beneath the ligament so that the ligament can return to its normal position.
Nucleus debulking has heretofore been performed conventionally, i.e., a relatively large incision is made and the surgeon outs through the membrane that overlies the ligament and through the ligament in order to reach the nucleus. The nucleus is out and sufficient amounts thereof are removed to thereby remove the pressure that was the source of the pain.
The tool usually employed to debulk the nucleus is known as a punch tool because it operates something like a paper punch, i.e., a shearing action accomplishes the desired cutting. More particularly, a typical punch tool has an elongate neck and the shearing mechanism is positioned at the distal end of that neck. A pair of handle members at the proximal end of the neck are squeezed by the surgeon and the squeezing action causes a first part of the shearing mechanism to slide with respect to a stationary second part of that mechanism, and nucleus matter between said parts is sheared from the main body of nucleus matter.
The cervical discectomy punches of the type just described operate in a batch mode, i.e., they shear a single piece of tissue for each entry to the surgical site through an incision. After each shearing action, the punch must be withdrawn, an irrigation tool must be inserted to irrigate the site and place the sheared piece of nucleus into suspension, the irrigation tool must be withdrawn, a suction tool must be inserted to vacuum the irrigation fluid and the sheared piece, the suction tool must be withdrawn, and the punch inserted for another shearing action. Thus, a surgeon might be required to make dozens of entries and exits through an incision in the course of a surgical procedure when using a conventional, one bite punch instrument. Such multiple entries, exits, and re-entries obviously extend the time required to perform the surgical procedure, and tire the surgeon and surgical assistants.
It is well known that arthroscopic surgical techniques require much smaller incisions and thus permit much faster patient recovery, thereby reducing the length of hospital stays and saving the expenses associated therewith, but arthroscopic tools capable of performing cervical discectomys do not appear in the prior art.
The prior art, when considered as a whole, neither teaches nor suggests to those of ordinary skill in this field how the conventional punch could be improved, or how the debulking procedure could be performed arthroscopically.